Mine roof supports

ABSTRACT

A MINE ROOF SUPPORT COMPRISES TWO UNITS WHICH CAN BE ADVANCED RELATIVE TO EACH OTHER. THE UNITS HAVE PARALLEL ROOF BEAMS EXTENDING IN THE DIRECTION OF ADVANCE, THOSE OF EACH UNIT ALTERATING IN THE BREADTH DIRECTION WITH THOSE OF THE UNIT. EACH UNIT COMPRISES TWO SUB-UNITS, EACH COMPRISING A CROSS BEAM AND SUPPORTING HYDRAULIC LEGS (THE SUB-UNITS BEING CONNCETED ONLY BY THE ROOF BEAMS OF THAT UNIT), AND CAN BE ADVANCED SEPARATELY BY A RAM, THE ROOF BEAMS CAN HAVE CANTILEVER BARS AT THEIR LEADING ENDS AND MEANS FOR RAISING PERMANENT ROOF BARS AT THEIR TRAILING ENDS. AN ANCHOR PLATE CAN BE SUSPENDED IN CRADLE-LIKE MANNER FROM ONE UNIT BY MEANS OF DOUBLE ACTING STAKER PROPS AND BE DISPLACEABLE BY MEANS OF ANOTHER DOOUBLE ACTING RAM.

NOV 23, 1971 ALLEN 3,621,661

MINE ROOF SUPPORTS Filed Oct. 28, 1969 3 Sheets-Sheet l INVENTORG ARCHEL'Q/US D/IM/SO/V ,QLLEN M lam/:1 W4

Nov. 23, 1971 A, LL N 3,621,661

MINE ROOF SUPPORTS Filed Oct. 28, 1969 3 Sheets-Sheet 2 INVENTORS BY gwflmwmf Wu,

NOV. 23, 1971 D LLE MINE ROOF SUPPORTS 3 Sheets-Sheet 15 Filed Oct. 28, 1969 J z A 9 w. i Q N9 OW w? @v m Q I NVE N TOR S AACf/EL 4/05 owasa/v AL L E/V,

United States Pate 3,621,661 MINE R0015 SUPPORTS Archelaius D. Allen, Leyland, England, assignor to Gullick Dobson Limited, Wigan, England Filed Oct. 28, 1969, Ser. No. 871,862 Claims priority, application Great Britain, Nov. 5, 1968, 52,291/68; Aug. 26, 1969, 42,424/69 Int. Cl. E2111 /44 lU.S. Cl. fill-45 D 13: Claims ABSTRACT OF THE DISCLOSURE A mine roof support comprises two units which can be advanced relative to each other. The units have parallel roof beams extending in the direction of advance, those of each unit alternating in the breadth direction with those of the other unit. Each unit comprises two sub-units, each comprising a cross beam and supporting hydraulic legs (the sub-units being connected only by the roof beams of that unit), and can be advanced separately by a ram. The roof beams can have cantilever bars at their leading ends and means for raising permanent roof bars at their trailing ends. An anchor plate can be suspended in cradle-like manner from one unit by means of double acting staker props and be displaceable by means of another double acting ram.

This invention is for improvements in or relating to mine roof supports.

One object of the invention is to provide a support, for use behind a heading machine, which will remain stable even in very poor roof and floor conditions.

Another object of the invention is to provide a support capable of working in the face junction, when retreating the panel, either by providing support under the permanent supports or by supporting the roof when the permanent supports are removed in front of the face advance.

According to the present invention there is provided a mine roof support particularly, but not necessarily exclusively for use in the gate of a mine working behind or straddling a heading machine, comprising at least two units, each unit having at least two spaced apart crossgirders, or members, mounted on extensible props or legs and longitudinal roof-engaging beams or members secured between said girders, the roof beams of each unit extending over the girders of the other, and means for advancing the units in turn, each unit acting in turn as an abutment for the advance of the other unit.

In one preferred embodiment of the invention there are two units each comprising two cross-girders, the girders of one unit being parallel with the girders of the other and being located therebetween. The longitudinal roof-engaging beams of the two units are also parallel with each other. With this arrangement one unit straddles the other, the roof beams of the latter projecting over the girders of the former. A hydraulic ram or rams is or are connected between at least one girder of each unit and serve to advance the units in turn.

The present invention is particularly, although not exclusively applicable to a mine roof support for use in the gate of a mine working behind a heading machine. By a feature of the present invention, as this heading support is advanced behind the heading machine there can be readily erected behind it a permanent support system for the roadway.

This feature resides in that the rear hydraulic legs or props of the advanceable support are provided with jib arms for carrying several roof bars. When these legs have been temporarily extended to secure the support between fioor and roof said roof bars are also applied to dfizlfifil Patented Nov. 23, 1971 the roof. Before the legs are retracted to allow the support to be further advanced, props are secured under at least one of said roof bars to hold it permanently in position.

The roof engaging beams can be provided with cantilever bars at their leading ends which bars are hinged to the leading ends of the beams and are pivotally displaceable about these pivots by means of hydraulic rams or other devices.

Conveniently the leading ends of the beams and the leading ends of the cantilever bars pivoted thereto in each unit fall on an arc of a circle corresponding to the are cut out by the heading machine itself. The leading ends of the beams and of the cantilever bars are staggered as between the two units by a distance amounting to one advancing step of the heading machine so that after every advance of the heading machine only one unit needs to be advanced.

An anchor plate for a conveyor can be suspended from the support by extendable members.

This anchor plate can be staked against unwanted movement from the roof support beams or girders and can subsequently be raised and re-positioned by means which can be disposed amongst the beams of the roof support or elsewhere.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings.

In the drawings FIG. 1 is a perspective view of one support,

FIG. 2 is a side elevation of another support,

FIG. 3 is a plan view of the support of FIG. 2, and

FIG. 4 is a detail view in side elevation illustrating another modification.

The support shown on the drawings comprises two units marked A and B respectively.

The unit A comprises two girder sub-units each comprising a cross-girder 10 mounted on hydraulically extensible props or legs 11. The legs 11 are double-acting so that they can be positively extended and positively retracted by hydraulic fluid. The girder sub-units are secured together and maintained in spaced apart relationship only by means of roof-engaging beams 12 secured in and to brackets 13 on the upper parts of the girders 10.

The unit B comprises girder sub-units each comprising a cross-girder 14 mounted on props or legs 15 similar to the props or leg 11. The girder sub-units of unit B 14 are secured together in spaced apart relationship only by roofengaging beams 16 secured in and to brackets 17 on the girders 14.

It will be noted that the beams 12 extend across and may bear on the girders 14!- of the unit B. In other words the unit A straddles the unit B. The cross-girders 14 of the unit B lie between the cross-girders 10 of the unit A and the ends of the beams 16 of the unit B project cantilever fashion across and may bear on the girders 10 of the unit A. It will be appreciated that the spacing between the cross-girders 14 is less than that between the crossby one advancing step of a unit.

It will also be noted that all the roof-engaging beams 12 and 16 lie in the same horizontal plane.

Each of the advancing rams for the units A and B has a piston rod 18 connected to one of the girders 10 of the unit A and a cylinder 19 connected to one of the girders 14 of the unit B. These connections may be pivotal or universal to allow for relative vertical movement between the girders 10 and 14.

A convenient length for the support is, for example, 18 feet and similarly the width may be 18 feet.

To advance the support, unit A is made non-supporting by retracting its legs 11 until its roof beams 12 are sup- 3 ported on the cross-girders 14 of the unit B. The doubleacting props 11 then continue to retract so that they are lifted clear of the floor. Unit A is then advanced by retracting the rams 18, 19 and its lateral position adjusted, after which it is reset to the roof by extending the props 11. Adjusting cylinders may be provided to control slewing of the advancing rams for this lateral adjustment of the support units.

Unit B is then similarly lowered onto the cross-girders 10 of the unit A and, after its props have been raised clear of the ground, advanced by extending the rams 18, 19. The unit B is then re-set to the roof.

An advantage of positively retracting the props or legs 11 and 15 clear of the floor, when a unit is to be advanced, is that the movement of the props or legs is not obstructed by poor floor condition, the roof structure of the units serving to guide the legs during advance.

A support as shown on the drawings may be used singly or any number of such supports may be used each support supporting, for example, an 18 foot length of heading. Preferably where two or more of such supports are used all the A units will be advanced in turn and then all the B units so that continuous lines of support are maintained. The supports can straddle a heading machine.

The support is reversible to provide support at a face junction. When supporting a retreating face junction access to the conveyor and mining machine is available between the props of unit B where, for example, a foot wide space is provided.

Chock type support units may be used, in retreat mining work, behind a support as above described to provide against caving, etc.

Only the longitudinal beams 12 and 16 are in contact with the roof and in the particular arrangement described where the length of the support is, say 18 feet, only a 2 foot space is left between the beams when all are set.

To sum up, some of the advantages of a support as above described are:

(a) Advance is not interfered with by floor obstructions.

(b) The props or legs only require small bases.

(0) The roof beams extend longitudinally.

(d) Positional adjustment may be provided.

(e) The support is adaptable to face end junction support with good access to the mineral cutting machine and the conveyor.

-(f) The support can be easily manufactured to suit different heights and widths of heading.

FIGS. 2 and 3 illustrate a modification in which there are provided two jibarms 45 each pivoted to a leg 11 and having a roof bar engaging claw 46. Roof bars (or a guided beam for traversably mounting a drilling machine) can be raised by the claws when the jibs are lulfed in synchronism by rams 47 for an operation on the roof. For example a roof bar in the claw can be clamped against the roof by fixed length or extensible, wooden or metal, props or legs.

FIGS. 2 and 3 also illustrate another modification. As before, the support consists of two units (A and B) having respectively the beams 12 and girders on the hydraulically extensible legs 11 and the beams 16 and girders 14 on the legs 15. The support is for straddling over a heading or coal winning machine 39 and coal removal means 40.

On the leading ends of the beams 12 and 16 there are cantilever bars 41 elevatable by means of hydraulic rams 42. The forward tips of the cantilever bars 41 on the beams 12 lie on an arc 43 of a circle of the same curvature as the sweep of the mining machine and forward tips of the cantilever bars 41 on the beams 16 are staggered relative to the tips of bars 41 on beams 12 and lie on a similar are 44 displaced by the amount of one advancing step of the heading machine, that is by half the stroke of the advancing rams, so that on advance one unit steps forward by two steps through the other unit.

The leading ends of the beams 12 and 16 lie on similar arcs.

Suspended in sliding cradle like manner from two of the roof beams 12 of one of the units, there is an anchor plate 49 in the modification of FIG. 4. This anchor plate 49 is suspended by double-acting hydraulically extensible and retractable legs 50 from a carriage 51 which engages in the sides of the two beams. A double acting hydraulic ram '52 is connected between an anchorage, such as a set leg 15, of the respective unit and the carriage, the ram 52 being synchronised with the rams 19 when the legs 11 of the respective unit are not under pressure so that anchor plate remains stationary while the respective unit is being advanced. Alternatively the legs 50 will be operated in coordination with the legs 11 of the respective unit so that the legs 50 are not braced when the unit is moved and preferably the ram 52 is simultaneously short-circuited on itself so that the anchor plate is retained in position by the conveyor end. Subsequently the anchor plate and a conveyor end thereon can be moved by the ram 52 to a new location after releasing the legs 50.

I claim:

1. A mine roof support, particularly for but not necessarily exclusively for use in the gate of a mine working behind or straddling a heading machine, which support comprises at least two units, each unit having at least two spaced apart cross-girder sub-units, each comprising a cross-girder and extensible props supporting the crossgirder, the sub-units in each unit being connected together only by longitudinal roof-engaging beams, the roof beams of each unit extending over the girders of the other so that each unit is supported by the other when its props are retracted to enable it to be advanced, and means for advancing the units in turn, each unit acting in turn as an abutment for the advance of the other unit.

2. A mine roof support as claimed in claim 1 in which the cross-girders of one unit lie between the cross-girders of the other unit and the spacing between the crossgirders of said unit is less than that between the crossgirders of the other unit by an amount equal to the advancing step of one unit relative to the other and in which the advancing means is a hydraulic ram.

3. A mine roof support as claimed in claim 1 in which the roof engaging beams are parallel and the roof beams of each unit alternate in the breadth direction with those of the other unit.

4. A mine roof support as claimed in claim 1 in which the props are double-acting hydraulic props.

5. A mine roof support as claimed in claim 1 having a pair of jib arms pivoted at the rear of one of the units for raising permanent roof bars against the roof, and means for luffing said jib arms.

6. A mine roof support as claimed in claim 5 wherein the jib arms are adapted to carry a guided beam by which a drilling machine can be mounted for drilling roof bolt holes.

7. A mine roof support as claimed in claim 1 having cantilever bars at the leading ends of said roof engaging beams for supporting the roof in advance of the support.

8. A mine roof support as claimed in claim 7 wherein the leading ends of the roof engaging beams of at least one unit lie on a curve and the cantilever bar tips of that unit also lie on an arc of a circle.

9. A mine roof support as claimed in claim 1 wherein the leading ends of the beams of each unit lie on a respective curve.

10. A mine roof support as claimed in claim 1 wherein the cantilever bar tips of the beams of one unit are staggered relative to the cantilever bar tips of the beams of the other unit by half the stroke of the advancing means.

11. A mine roof support as claimed in claim 1 having suspended from beams thereof an anchor plate, whereon a conveyor end can be mounted for movement.

12. A mine roof support as claimed in claim 11 wherein the anchor plate is suspended from the beams by double acting hydraulic legs.

13. A mine roof support as claimed in claim 11 having ram means for displacing the anchor plate relative to the support.

References Cited UNITED STATES PATENTS Joseph 6145 Dornmann 248-357 X Groetschel 61-45 Dommann 299-33 6 FOREIGN PATENTS France 61-45 France 61-45 Germany 61-45 Great Britain 61-45 D Great Britain 299--31 Germany 61-45 D US. Cl. X.R. 

